It is every bit a process. I guess you have answered my question which was primarily, do people selling Elvis LCs stick in the word Musical on their sales pitch or subject line.
For my part, I rely on people putting the word Bond into the subject line. But if that isn't there, I will regularly go deeper into film titles - of which, there are only 25. That said, and pertinent to your task, sellers of such material tend not to stick in the all encompassing word, Espionage. And you are looking at more titles than 25, I am sure...!
Well, I tend to separate stuff into categories. Fred and Ginger, pre-1940, golden age 1940-70, modern such as Little Shop of Horrors or Grease. Even there, I will work to get complete sets of the iconic titles from Astaire, Kelly, Garland, Keel, Ann Miller, etc. The lesser stuff I only go after a single card, or an opportunistic purchase.
I bet your Bond stuff gets divided into at least Connery, Moore others, and possibly those that Flemming actually wrote.